Manufacture of soles



H G A N A v A c .J

MANUFAC TURE OF S OLES Filed Deo. 17, V1934 NQ@ l I E /NV/VTUAQ- w00A l f V`ab l* @gw Patented May 26, 1936 UNITED STATES PATENT GFF'ICE MAN UFACTURE F SOLES Application December 17, 193,4, Serial No. 757,834

6 Claims.

This invention relates to improvements in the manufacture of soles for boots and shoes.

It is desirable to have the soles of boots and shoes flexible in their foreparts so that they will bend freely as required to accommodate the natural flexure of the feet in walking, i. e., about axesextending crosswise of the sole, and it is also desirable in most shoes to have the soles relatively stiff orrelatively iniiexble at right angles to the directions in which they are bent in use, i. e., about axes extending lengthwise of the sole. Ihis is particularly true with respect toI insoles and more especially with respect to the insoles of shoes of the type in which the margin of the upper is overlasted upon the insoles and is directly secured to both the insole and the outsole b-y means, for example, of through-andthrough` stitching or cement.

In view of the foregoing, objects of the present invention are to provide an improved sole having the desired characteristics above pointed out and an improved method of making such soles.

To the accomplishment of the above objects the invention, in one aspect, provides a method of making soles, which are relatively flexible about transverse axes and relatively inexible about longitudinal axes, which consists in grooving one side of a sole in a crosswise direction, and applying stiffening material to those portions only of the sole which constitute the walls of the grooves. As herein exemplified with respect to the treatment of insoles, a substantial number of grooves are cut in the forepart portion of the lower surface of an insole, that is, the surface which is to face the outsole in the shoe, and the Walls of the grooves and the portions of the sole material immediately adjacent to the walls of the grooves are stiffened, by the application thereto of a liquid stiffening medium, such for example as pyroxylin cement. A sole thus treated will be reinforced to a substantial extent by means of the stiffening medium against bending about axes extending crosswise of the grooves. On the other hand, the resistance of the sole to bending about axes extending lengthwise of the grooves has been reduced by the grooving operation. Inasmuch as the sole has been made thinner along the lines of the grooves and while vthe sole substance has been stiffened along the lines of the grooves, the depth of the grooves and the thickness of the coatings of stiffening material are made such that in practice the soles have been found to flex more freely in directions in which they are required to bend in use than soles which have not been thus treated.

Considered in another aspect, invention is to be recognized as residing in an improved sole for shoes having a plurality of grooves extending crosswise of the sole, the walls of the grooves being reinforced by stiffening material, for example, pyroxylin cement. I

The invention will be explained with reference to the accompanying drawing, in which Fig. 1 is a perspective view of the forepart of an insole which has been treated in accordance with the present invention;

Fig. 2 is a fragmentary sectional view illustrating the operation of forming the grooves in the sole;

Fig. 3 is a fragmentary sectional View taken along the line III-III of Fig., 1 as the sole appears before the stiffening mediumv has been applied;

Figs. 4 and 5 are views similar to Fig. 3 but showing alternative forms of grooves;

Fig. 6 is a fragmentary sectional view illustrating the manner of applying the stiffening medium to the grooved portions of the sole; and

Figs. 'l and 8 are sectional views similar, respectively, to Figs. 3 and 5 but showing the soles as they appear after the stiffening medium has been applied.

In carrying out my improved method I prefer to provide a plurality of grooves I0 in an insole I2 substantially as indicated in Fig. 1, the grooves being preferably formed in the lower or outsoleengaging surface of the forepart portion of the insole and preferably the grooves extend entirely across the insole in directions substantially parallel to the break line, i. e., the line where the sole breaks or bends in the shoe at the junction of its shank and forepart portions. As indicated in Fig. 2, the series of grooves may advanta-` geously be formed in a single operation by means of a machine comprising toothed upper and lower feed wheels I4, l5, a work supporting table I6, through which the lower feed wheel projects, and a series of grooving knives, one of which is shown at I8, to which the insole is advanced by means ofl the feed rolls. The grooving knives I8 may be shaped to form grooves which are arcuate in cross-section, as indicated in Figs. 1, 3 and '7, or they may be shaped to form substantially rectangular grooves, such as the grooves |00 shown in Fig. 4, or V-shaped grooves, such as the grooves |02 shown in Figs. 5 and 8.

After a sole has been grooved in the manner already described the grooved portions of the sole are stiffened, as herein shown, by coating the walls of the grooves with a liquid stiifening medium, such as pyroxylin cement, the coatings of cement being indicated at 20 in Figs. 6 and 7, and at 200 in Fig. 8. The liquid stiffening medium may be applied to the grooves in a sole by means of a series of extruding nozzles, one of which is shown at 22 in Fig. 6, while the sole is supported upon a suitable supporting table and is fed past the nozzles by suitable feeding means, there being shown in Fig. 6 a work supporting table and upper and lower feed Wheels similar to the table and feed wheels shown in Fig. 2.

Preferably the cement or other stiffening medium is so applied as only partially to fill the grooves in the sole, as indicated in Figs. 7 and 8. The stfening medium will of course penetrate more or less into the substance of the sole in the immediate vicinity of the grooves. After the cement has dried it has been found that the soles have been stiifened to a substantial extent against bending about axes extending crosswise of the grooves and lengthwise of the sole. On the other hand, while the sole material in the immediate vicinity of the walls of the grooves has been stiiened by means of the cement, nevertheless, the resistance of the sole to bending about axes extending lengthwise of the grooves and crosswise of the sole has been reduced by the grooving operation to such an extent that the soles have been rendered capable of bending more freely about these axes than if they had not been treated. This may be due partially to the factthat the cement in each groove is not of maximum thickness throughout the entire width of the groove so that it is substantially less effective to reinforce the insole against bending about axes crosswise of the sole than it is about axes lengthwise of the sole.

Having described my invention, what I claim as new' and desire to secure by Letters Patent o-f the United States is:

1. 'I'hat improvement in methods of making soles which are relatively iiexible about transverse axes and relatively inilexible about longitudinal axes which consists in grooving one side of a sole in a crosswise direction, and applying sti'enng' material to those portions only of the sole which constitute the Walls of the grooves.

2. That improvement in methods of making insoles which consists in forming a plurality of parallel grooves extending across an insole, and coating with stiifening material only those portions of the insole surface which constitute the Walls of the grooves.

3. That improvement in methods of making shoes having flexible sole parts which consists in forming a groove in the bottom surface of the forepart of an insole, the groove extending across the insole, and coating the Wall of the groove throughout its length with pyroxylin cement.

4. A sole having a plurality of grooves extending across it, the walls of the grooves being reinforced throughout their length by stiffening material.

5. An insole having a plurality of grooves extending across it, the grooves having their walls coated throughout their length with pyroxylin cement.

6. An insole having a plurality of spaced grooves extending transversely of the insole, those portions only of the insole which constitute the Walls of the grooves being coated with a stiflening medium and the insole material adjacent to said walls being impregnated by said medium.

JAMES CAVAN AGH. 

